Railroad signal



Apr. 10, 1923.

Hal.

5. M. DONALDSON RAILROAD SIGNAL Filed Jan. 29, 1925 5 sheets-sheet l Apr. 10, 1923.

RAILROAD SIGNAL Filed Jan. 29, 1925 3 shedssheet 2 Elmo my 1,451,438 s. M. DONALDSON Patented Apr. 19, 1923.

m STATES STEPHEN Mi nonALnson, or MEG-GETT, scorn oanonnva g I nAILnoAD SIGNAL.

"""Application med .l'anuary 29, 1923. Serial No. 615,703.

volves both a visual and audible signal actu-i ated by energy from an approaching train or locomotive. herein 15 illustrated in connection with a single track railway, and the signalsare.

adapted for actuation upon the approach of Y a train'from either of the two directions, butit'will be understood that the. signal mechanism may beadapted for use on. double track railways when required. i

The invention'contemplates the use of "a signal tower located in proper position at a:

highway, grade fcrossing' over the railroad, 25. in which tower theoperating mechanism and the audible signal, or bell; are supported together with the visual signal :or flag. By means of the train actuated mechanism the bell is sounded and the 'flag waved at. the approach of'a train as a warning signal, as

will be hereinafter pointed out and claimed.

, In the accompanying drawings have illustrated one complete example of the physical embodiment of myinvention as an equipment fora single trackrailroad, where in the parts are combined and arrangedao cording to one 'mode'l have devised'for the practical application of the principles of my invention. H 7 g Figure '1 is a View elevation of the signal tower. showingjindotted linesthe movement f f the} visual signal or flag whenj actuated upon thefapp'roachof a train. I

' Figure 2 is an enlarged, vertical sectional view of the signal *towe'r, part of the signal arm or flag supporting member being broken away atthe ,top. i Figure 3 's adetail perspective view of the belltap'per; showing its suspension means from'the signal arm. I

. Figure 4 is a vertical sectional viewof the signal tower, as seen the in' lfig Figure'5 is a detail view showing one of the tripping dogs, with its" housing or box The invention as embodied in; section, and illustrating its relation to the railway track rail; I

Figure 6is a detail view ofone of the rolller supports forthe draw rod of the sig- Figure 7 is a horizontal sectional view at the .base of the signal'tower, showing the actuating levers and connections."

Figure .8 is a view in side elevation of one of the tripping dogs, with "parts in section.

T FIEQ- Figure 9 is a diagrammatic view showing the grade crossing and railroad tracks, and

relative position of the signal equipment.

The standard ties 1 andrailsQare illustrat'ed' and so much of a. singletrack rail-' way is shown as is necessary for an understanding ofmy invention, itf being understood that the duplex actuating mechanism at the sides ofthe gradecrossingisactuated j byan approaching train through the instrumentality of a tripping dog as' 3,.locate'd above the railway ties, and at the. track side. The tripping dog is provided with a slotted housing 4, and the, dog is pivoted to oscillate on an'axle or shaft '5 supported in the plate 6 that is attached to adjoining ties as usual. The tripping dog is fashioned with a weighted portion or weight 7 "to maintain it normally in upright or vertical position atthe outer side ofthe track rail 2, as indicated in Figure. 5. i

A pair oflaterally projecting trunnions 8 are fashioned on the tripping dog, below its pivotal point, for co-action withthe draw rod 9. The'tripping" dog is preferably of metal and. of course of suflicient strength to withstand the shocks towhich it will be subjected, while the draw'rod 9 [one at each side of the crossing] may be made of pipe sections in usual. manner. -The draw rod coacts with thetrunni'onsflof the trippingdog through the .instruinentality of a bifurcated hook 10 which is designed to engage the trunnions in such.,manner that the rod will be drawn; tothe right infFigure 8 fora working stroke, and will permit the tripping dog toswing freely on an idle stroke im parted to the dog. Thehook is fashioned with'a socket head 11 securedi'asby screw threads on the draw rod and thisheadengages against ,an abutment 12 ins de the housing when the draw rod is in normal a carried, as indicated by dotted lines in Figure 5,. the locomotive, which moves in the direction indicated by the arrow in Figure.

8 to ride down the tripping dog, and through the trunnions and hook, the swinging motion 01": the tripping dog is converted to a draw motion or the draw rod 9. guided in bearing brackets or plates let lo cated at suitable intervals along the track side, and it will be understood that the two trippingdogs are positioned at the proper distance from the grade crossing'to give ample time for the signalling of the ap r on 'thedraw rod and a bearing bracket 3.3

throu h which the draw rod ma reci rocats or slide. The collar. forms an abutment and is held against the bearing bracket19 for the draw rod, and it will be apparent that the draw rod, in Figure 7, may be pulled to the right to compress the-spring,and after.

the trip arm of the locomotive has passed over the tr pping dog and released the lat "-ter. the spring, by expansion pulls the draw rod to the left at the right side of. Figure 7,

thus restoring the draw rod tonorn'ial position. v

The ad o ning ends of the draw rods are the form of a link as 20 and 21, and each link is pivoted to an angular lever arm as 22 and 23. The lever arms are disposed in parallelism at right angles to the draw rods and pivoted at 22 and 23' respectively to swing in, horizontal planes, the pivoted links 20 and 21 being connected in such manner as to permitthe draw rods to swing their respective lever'arms as one. or the other of the draw rods is actuated.

Each lever arm is fashioned with a pivoted extension, as 2* and 25, and these extensions are, .pivoted to their respective arms. at 26 in order thattheymay swing slightly in a ,vertical plane .as they are carried by the '-l ever1arms when the latterswing in their l'xor zgntal planes. This double pivot arrangement enables the free ends of the lever arms to be elevated slightly as the lever. arms are swung on the r p vots in one direction, or

the werlring stroke, and said extensions are depressed on their idle or. return-strokes.

111$ movement of the pivoted extensions ofthe lever. arms is imparted thereto through agu1d'efplate27 and its guide slot 28, the

A l being located in position at right anges to the plvoted levers and their extensions. and the upper. and lower walls of i he inclined as required.

The latter is In Figures 2 and 7 it will be seen that when the lever arm 23 is actuated by the draw rod 9, the pivoted extension 25 will be swung to the left. As said extension is swung to the left it rides up the curved and upwardly inclined portion of the slot 28, at the movement to a pendulum or oscillating arm 29, which is supported to swing on its trunnions 30 in the bearings 31. The bearings are supported in a frame 32, and a housing or tower encloses the oscillating arm and its connections, said housing being indicated by the numeral 33. It willbe apparentthat.

the lower end of the pendulum or oscillating arm is located in thepath ofeither of the two lever extensions 24 and 25, and that when either of these extensions is actuated it I will rise to the proper elevation to contact with the free end of the oscillating arm and swing the latter. on its trunnions. One stroke of the lever extension is sufiicient to set in motion the oscillating-arm, and immediately the lever extension is returned to normal position, the oscillating arm however swings until returned to normal position by gravity. I I

For varyingthe-length of the stroke, otthe pendulum and thereby increasing or decreaseaoh equipped with a pivoted extension in ing the vraj-pidityoi" its movement, I provide a weight 34:, which moves between guides 35 fixed at the inner sides ofthe housing, and the weight may be supported in adjusted position by a cotter pin 36 inserted through one of the several holes 37 in the arm.

Through the oscillating movement of the suspended arm 29 the audible signal is sounded by means of a bell 38 which is supported from the fixed bracket 88. near the top and inside of the tower 33. A bell tapper or ball 39 is suspended by a suitable suspension device 40 from the oscillating arm at 41 above the bell, and the tapper hangs in proper position to swing and contactwith the bell for ringingthe latter as theta-pper swings back and forthwith the oscillating arm. 2 A guide bracket 42 is attached. to the oscillating arm andprovided with a guidev slot for the suspension device of thetapper, to restrain and guide the bell tapper in its movements.

I Thevisual signal is. carried at the upper end of the oscillating arm, which passes through a slot 43 in the top of the tower, and a flag 4A of usual type is attached at the upper end of the oscillating arm. Said in dotted lines in Figure 1 when the signal actuated.

flag isv waved back and forth as indicated Other necessary accessories, while not illustrated will of course be supplied, as for instance slots 45 in the wall of the tower are used to permit movement of sound waves from the bell, and doors asses-7, 48, are providedto give access tothe'interior of the tower when required.

From the above description taken in connection with my drawings it will be apparent that I have provided a signal installation of this type which is comparatively I simple in construction, durable, and efficient tripping dog operatively connected to the.

in performing its required functions.

Having thus fully described my invention, what I claim and desire to secure by Letters Patent is 1. The combination with an oscillatable signal arm, of a pivoted lever adjacent to the free end of said arm, a draw rod opera atively connected to said lever, and a vehicle actuated tripping dog operatively connected to said draw. rod, and means for -guiding said lever' into Contact with the free end of said signal arm to move the latter upon actuation of said tripping dog.

2. The combination with an oscillatable signal arm, of a pivoted lever normally out of operative position with relation to the free end of said arm,-a draw rod connected to said lever and means for retaining said rod in normal position, a vehicle actuated draw rod, and means for guiding said lever into position for contact with the free end of said signal arm upon a working stroke of said tripping dog.

3. The combination with an oscillatable signal arm, of a pivoted lever arm, a draw rod and tripping dog, a pivoted extension on said lever arm, a plate adjacent said signal arm, and said plate having an instroke.

clined slot for said extension whereby the latter is guided for impact with said signal arm when the tripping dog is actuated.

4;. The combination in a railway signal with a pivotedvehicle actuated tripping dog. having oppositely disposed trunnions,

of a draw rod and a socket head thereon, and

a bifurcated hook on said head loosely en gaging said trunnions whereby the dogmay operate the draw rod on'its working stroke and swing freeof the hook on its return 5. The combination in a railway signal with a pivoted vehicle actuated tripping dog having oppositely disposed trunnions and a'weight on said dog for normally-holding the latter in operative position, of a draw rod and head thereon, and means on said head operatively connected to said trunnionsuwhereby'the dog may operate the rod on its working stroke'and by gravity 6. The combination in a railway signal with --an osclllat-able arm and vehlcle actuated means for swinging said arm, of a stationary bell, a tapper suspended on; said STEPHEN M. noNAL so-N.

.return to normal position, and swing freely I on an idle stroke. 

